Highly improved transportation system

ABSTRACT

The disclosure is of a transportation system which includes an elongated guidebeam having three spaced apart running surfaces. Two of the running surfaces as substantially vertical to accommodate wheels rotating about vertical axles and the third running surface is substantially horizontal to accomodate wheels rotating on horizontal axles. Wheels which rotate on a normally vertical axle and wheels which rotate on a normally horizontal axle are connected to a rack which is adapted to move along the running surfaces of the guidebeam. The wheels connect the rack on the side of the guidebeam in cantilever fashion. Connecting switch sections are provided at desired locations on the elongated guidebeam to connect two or more guidebeams. The switch sections have no moving parts and cooperate with wheels of the rack which are movable on the guidebeam by self-contained means carried on the rack in a direction normal to the direction of travel of the rack to provide for high speed switching of the rack between an upline guidebeam and one of two or more spaced apart downline guidebeams and between two or more spaced apart upline guidebeams and a single downline guidebeam.

United States Patent 1191 Jacobs, Jr. et a1.

[ Sept. 25, 1973 HIGHLY IMPROVED TRANSPORTATION SYSTEM [76] Inventors: Justin M. Jacobs, Jr., 1245 Jones St., San Francisco, Calif. 94109; Neil S. Stafford, Rt. 3 Box 355, San Jose, Calif. 95121 [22] Filed: Dec. 28, 1971 21 Appl.No.:212,906

Related U.S. Application Data [63] Continuation-impart of Ser. No. 861,843, Sept. 29,

[969, Pat. No. 3,659,529.

Primary Examiner-Gerald M. Forlenza Assistant Examiner-D. W. Keen Attorney-Edward J. Keeling [5 7 ABSTRACT The disclosure is of a transportation system which includes an elongated guidebeam having three spaced apart running surfaces. Two of the running surfaces as substantially vertical to accommodate wheels rotating about vertical axles and the third running surface is substantially horizontal to accomodate wheels rotating on horizontal axles. Wheels which rotate on a normally vertical axle and wheels which rotate on a normally horizontal axle are connected to a rack which is adapted to move along the running surfaces of the guidebeam. The wheels connect the rack on the side of the guidebeam in cantilever fashion. Connecting switch sections are provided at desired locations on the elongated guidebeam to connect two or more guidebeams. The switch sections have no moving parts and cooperate with wheels of the rack which are movable on the guidebeam by self-contained means carried on the rack in a direction normal to the direction of travel of the rack to provide for high speed switching of the rack between an upline guidebeam and one of two or more spaced apart downline guidebeams and between two or more spaced apart upline guidebeams and a single downline guidebeam.

17 Claims, 46 Drawing Figures PMENTEDSEPZSIQH sum 1 or 8 INVENTORJ JUSTIN M. JACOBS JR. NEIL S STAFFORD W ATTORNEY PAFENTEU 2 3 SHEU 5 OF 8 PATENIEnsEnsma V 3,760.7)

saw n ur 8 mm" 4Q HEP mt QNF 05 mb 5 T 1 t am u o o m 4 .4 A 4 4 A tw .0? m Nri|| kv m|bm||=iw lLii uiiirrlwlriri Q i I i 1 L 5 l HIGHLY IMPROVED TRANSPORTATION SYSTEM RELATED APPLICATIONS This application is related to our application Ser. No. 746,884, filed July 23, 1968 for Transportation System and now US. Pat. No. 3,606,839 and is a continuation in par to our pending application, Ser. No. 861,843, filed Sept. 29, 1969 for Improved Transportation System, now US. Pat. No. 3,659,529. The disclosures of these applications are herein incorporated by reference.

FIELD OF THE INVENTION This invention relates to a transportation system which includes an elongated guidebeam having running surfaces for 'cantilevering a rack on, and more specifically the invention deals with a transportation system having connecting switch sections for switching a rack between upline and downline guidebeams without the necessity of moving parts in the connecting switch sections.

BACKGROUND OF THE INVENTION A particular problem which has plagued most fixed rail guidebeam transportation systems has occured in switching the moving member or rack from one fixed rail section to a second fixed rail section which is either horizontally or vertically diverging from the main section. For example this problem was exemplified by conventional railroad transportation systems wherein it has been necessary to provide a moving switch section between two diverging portions of the track to allow switching of the train from one rail section to a second diverging rail section. Even a more serious problem has been encountered in monorail and cantilevered systems where there were no satisfactory switching methods.

In the first above mentioned related applications, Ser. No. 746,884, and now US. Pat. No. 3,606,839, we disclosed a method of vertically switching a cantilevered rack from an upline guidebeam to a downline guidebeam utilizing a movingsection positioned pivotally on an intermediate connecting. guidebeam switch section between two diverging guidebeams. It has been found that while movable switch sections of this nature are operative to provide for switching a cantilevered rack, it is necessary, particularly in high density, high speed flow of racks in a cantilever system, that switching be accomplished without need for a movable section in the guidebeam switching section. This is particularly necessary where a computerized transportation system is desired which will allow for closely spaced high speed travel of a number of individual racks along a guidebeam system which may include many interchanges and switches. There will be many racks moving at very closely spaced intervals along the main guidebeam in such a system and it is often desirable to switch some of the racks to alternative guidebeams while allowing other of the racks to pass through on.the main guidebeam. The time lag required by the moving section of the heretofore disclosed connecting guidebeam switch section requires that a definite time interval and substantial leadway be maintained between the racks traveling on the main line guidebeams. Thus when utilizing a moving switch section the racks must maintain certain spaced intervals depending upon the speed and the time lag in the switch.

In our second above mentioned application Ser. No. 861,843 now US. Pat. No. 3,659,529 a unique transportation system was disclosed which has connecting switch sections having no moving parts. The switch sections cooperated with movable means, such as extendable and retractable wheels, of the rack to provide for selective high speed switching both in horizontal and vertical modes of the rack between an upline guidbeam and one or more spaced apart downline guidebeams and between two or more spaced apart upline guidebeams and a single downline guidebeam. The method and apparatus disclosed in our application Ser. No. 861,843 utilized an extendable and retractable support wheel rotating around a normally horizontal axle of a rack in cooperation with ramps or through paths in certain portions of a switch section to selectively elevate or not elevate guide wheels rotating around normally vertical axles of a rack to selectively switch the rack on the guidebeams.

The present invention is directed to increasing the flexibility of a guidebeam transportation system by providing for selectively moving the guide wheels of a rack in a direction normal or transverse to the direction of travel of the rack without the use of a ramp in the guidebeam switch section. This mode of switching is particularly useful in horizontal switching of racks. The system of the present invention, of course, may be advantageously incorporated in a rack of our system disclosed in Ser. No. 861,843 and thus also utilize ramps of the guidebeam switch sections in addition to the selfcontained vertical movement of the present invention to provide for multiple switching of racks at high speed on relatively short switch sections.

A BRIEF DESCRIPTION OF THE INVENTION The present invention includes an arrangement of guidebeams connected by specially devised nonmoving connecting guidebeam switch sections which cooperate with racks assembled in accordance with the inventionto permit switching of the racks from the mainline guidebeam to a selected guidebeam of two or more spaced apart guidebeams. The racks utilize selfcontained means to selectively move guidewheels vertically on the guidebeam to determine the path of the rack through the switch section. The guidewheels are moved by self-contained equipment carried by the rack. Three embodiments of racks are disclosed in accordance with the invention. Connecting switch sections are described for each type of rack. The method and apparatus of the present invention are useful in the horizontal switching of cantilevered racks. The adaptability of'switching of the present system is particularly useful when combined with our previous non-moving switch system in providing a complete network guidebeam system which is compatible with a wide range of topographical and station requirements.

The racks used in accordance with present invention are cantilevered on a guidebeam by means of upper and lower guide-wheels and a support wheel. The racks include a frame having the wheels mounted thereon. The wheels of the frame include two horizontally spaced apart upper guide wheels rotatably mounted on normally vertical axles of the frame. Two horizontally spaced apart lower guidewheels are also rotatably mounted on normally vertical axles of the frame. At least a pair of spaced apart support wheels are rotatably mounted on horizontal axles of the frame. The support wheels are located between the upper guidewheels and lower guidewheels. Self-contained means are provided on the rack for moving the guidewheels in a direction normal to the direction of travel of the rack which, when the wheels are rotated, directs the rack along a selected path through the connecting switch section to a selected downline guidebeam.

OBJECT OF THE INVENTION The object of the present invention is to provide a transportation system for moving people, freight, vehicles and other payloads over a minimum right of way which transportation system includes an elongated guidebeam system having non-moving switch sections for carrying a special rack at high speeds and which provides for switching from an upline guidebeam to one of two or more downline guidebeams and also merging to a downline guidebeam from two or more spaced apart upline guidebeams without the use of moving parts in the connecting switch section.

BRIEF SUMMARY OF THE DRAWINGS FIG. 1 is a schematic perspective view and illustrates the modes of switching that are selectively accomplished in accordance with the present invention;

FIG. 2 is an elevation view and illustrates the preferred rack assembled in accordance with the invention;

FIG. 3 is a side elevation view and illustrates the preferred rack assembled in accordance with the invention;

FIG. 4 isa bottom view and illustrates the preferred rack assembled in accordance with the invention;

FIG. 5 is an elevation view and illustrates an alternative rack assembled in accordance with the invention;

FIG. 6 is a side elevation view and illustrates the alternative rack assembled in accordance with the invention with the guide wheels in the lower position;

FIG. 7 is a side elevation view and illustrates the alternative rack assembled in accordance with the invention with the guidewheels in the upper position;

FIG. 8 is a bottom view and illustrates the alternative rack assembled in accordance with the invention;

FIG. 9 is a side elevation view of a connecting switch section providing horizontalswitching in accordance with the invention; a

FIGS. 9A-9E are sectional views taken as indicated from FIG. 9;

FIG. 10 is a partial top view of the connecting switch section of FIG. 9;

FIGS. 10A and 10B are sectional views taken as indicated from FIG. 10;

FIG. 1 l is a side elevation view with portions broken away for clarity of presentation of a connecting switch section providing combined switching in accordance with the invention;

FIGS. llA-llE are sectional views taken as indicated from FIG. 11;

FIG. 12 is a partial top view of the connecting switch section of FIG. 11; g

FIG. 12A is a sectional view taken as indicated from FIG. 12;

FIG. 13 is an elevation view ofa downline connecting switch section providing combined switching in accordance with the invention;

FIGS. l3A-l3E are sectional views taken as indicated from FIG. 13;

FIG. 14 is a partial top view of the connecting switch section of FIG. 13;

FIGS. 14A and 14 B are sectional views taken as indicated from FIG. 14-;

FIG. 15 is an elevation view and illustrates an alternative rack assembled in accordance with the present invention;

FIG. 16 is a side elevation, with portions in section, and illustrates the alternative rack assembled in accordance with the invention;

FIG. 17 is a side elevation of an alternative embodiment of switch section assembled in accordance with the invention;

FIGS. 17A-l7F are sectional views taken as indicated from FIG. 17;

FIG. 18 is a partial top view of the connecting switch section of FIG. 17; and

FIGS. 18A and 18B are sectional views taken as indicated from FIG. 18.

DETAILED DESCRIPTION OF THE EMBODIMENT OF THE INVENTION FIG. 1 shows a prospective schematic illustration of the modes of switching that may be accomplished in accordance with the present invention. Switching is accomplished without the use of moving parts in the connecting guidebeam switch section. In accordance with the present invention when utilizing self-contained means carried on the rack to raise or lower the guide wheels, the rack may be switched horizontally from a main guidebeam to the left or to the right to diverging downline guidebeams, or may be continued through such connecting switch section on the mainline guidebeam. As is evidenced by the reverse arrows the switch section can be modified so that such horizontal switching may be accomplished into a through mainline guidebeam from guidebeams merging from the left or the right.

When utilizing a rack having both self-contained means for vertically moving the guide wheels in accordance with the present invention and having extendable and retractable support wheels, such as taught in our application Ser. No. 861,843 and adaptable with the present invention, the rack may be moved rapidly through a very complex interchange or a series of closely spaced-apart switch sections and switched vertically or horizontally or both in sequence without the need to reset the wheels after each portion of the switch section is passed. For example the guide wheels on a rack can be programmed to make the first possible right hand horizontal turn of FIG. 1. Then without resetting the guide Wheels or support wheels the rack can be quickly switched through up to live or more of the next diverging horizontal guidebeams by proper prior programming or setting of the guide wheels and support wheels. In a similar manner vertical switching can proceed of follow horizontal switching by proper prior programming or setting of the support wheels and guide wheels as illustrated downline in FIG. 1. Utilizing both moving guidewheels and moving support wheels many combinations of switching are provided in accordance with the present invention. FIG. 1 is used to illustrate some of the modes of switching possible in accordance with the invention.

Refer now to FIGS. 2, 3, and 4. FIG. 2 is an elevation view of the preferred rack assembled in accordance with the present invention. FIG. 3 is a side elevation view of the preferred rack and FIG. 4 is a bottom view of the preferred rack of the present invention. The rack 20 has a pair of horizontally spaced apart upper guide wheels 33 and 35 and a pair of horizontally spaced apart lower guidewheels 37 and 39. Each of the guidewheels is rotatably mounted on a normally vertically extending axle. Support wheels 38, 40, rotatably mounted on normally horizontal axles 18, 19 are used to move the rack along the running surfaces of the guidebeam. Power sources 85, 86 are connected to the support wheels to drive the wheels. The rack 20 includes a frame 22 which has overhanging arms 62, 63 which extend above the upper portion of the frame 22 to permit the upper guidewheels 33, 35 to engage the guidebeam on the inner facing running surface 12 which forms the upper guidewheel running surface.

The upper guidewheels 33, 35 are movable in a direction normal to the direction of travel of the rack as indicated in phantom in FIGS. 2 and 3. The lower guidewheels 37, 39 are mounted on normally vertical axles 43, 45 of the frame 22. A pair of idler lower guidewheels 80, 82 are also mounted on normally vertical axles 83, 84 of the frame and are useful to bridge gaps in the guidebeam switch sections as hereafter described. The lower guidewheels 37, 39 are also movable in a direction normal to the direction of travel of the rack as also shown in phantom in FlGS. 2 and 3. In order to select a desired path through a guidebeam switch section the upper guidewheels 33, 35 and the lower guidewheels 37, 39 are moved in a complementary fashion. Thus when the upper guidewheels 33, 35 are extended to the position shown in phantom, the lower guidewheels 37, 39 are retracted and moved closer to the frame as also indicated in phantom. The movement of the guidewheels in a direction normal to the direction of travel of the rack is preferably done when the rack is moving along the guidebeam to reduce friction caused by such vertical displacement of the guidewheels on the guidebeam running surfaces.

Self-contained means are thus provided on the rack for displacing the guidewheels in a direction normal to the direction of travel of the rackover a guidebeam. The movement is generally in a vertical direction with respect to the guidebeam. This transverse or vertical movement is done when it is desired to switch a rack from one guidebeam to another and realignment of the guidewheels is necessary to select the proper path through the switch section. In this aspect of the present invention the upper and lower guidewheels are moved up or down with respect to the rack. Appropriate linkage is used to extend or retract the axles of the guidewheels to thus move the guidewheels normal to the direction of movement of the rack and raise or lower the guidewheels with respect to the running surfaces of the guidebeam.

A hydraulic system may be used in conjunction with mechanical linkage to elevate and depress the guidewheels. For example a hudraulic cylinder 50 is connected to upper guidewheel 33 and lower guidewheel 37 by appropriate mechanical linkage. The master hydraulic cylinder 50 is also connected to upper guidewheel 35 and lower guidewheel 39 through a similar mechanical linkage. The operation of the hydraulic cylinder 50 is controlled by a suitable master control 51. Referring to the left-hand side of FIG. 2, a pushrod 52 extends from the hydraulic cylinder 50 and is connected to a pushrod extension 54 by means of a pin connected link 56. The pushrod extension 54 is connected to a pivotally mounted bell crank 58 by means of a pin 60. Th bell crank 58 is pivotally mounted on the frame 22 by a pin 62. The other arm of the bell crank 58 is pivotally connected to a pair of pushrods 64 and 66 by means of pins 70 and 72. When the bell crank 58 is pivoted about pin 62 rod 64 and rod 66 are pushed or pulled depending on the direction of movement of the bell crank. This up or down movement is transmitted to the guidewheels 33, 37 by suitable linkage. Thus the axle 43 of lower guidewheel 37 is reciprocally mounted in bearing 42 and a pin connection 47 is used to connect rod 66 with the end of axle 43. The guidewheel 37 is rotatably mounted to the axle. Wheel 37 is moved between the positions indicated in FIG. 2 by movement of the above described linkage when the master cylinder is activated.

The upper guidewheel 33 is extended or retracted in complimentary relationship and in tandem with the lower guidewheel by extending or retracting axle 41. The axle 41 is reciprocally mounted in a bearing and pushrod 64 which is curved at its top end to provide a pin 78 connecting into the eye 79 at the lower end of axle 41.

The other guidewheels 35, 39 are moved in complimentary fashion by linkage extending from the other side of the master cylinder 50. Note that the bell crank 258 is mounted in reversed fashion compared to bell crank 58 so that the movement of all the guidewheels is complimentary. That is to say when the upper guidewheels 33, 35 move up or away from the frame 22 then the lower guidewheels 37, 39 also move up or in this instance toward the frame 22. In the right-hand side of FIG. 2, a suitable pushrod 252 extends from the hydraulic cylinder 50 and moves in the same direction as pushrod 52, and is connected to pushrod extension 254 by means of a link pin 256. The pushrod extension 254 is connected to a pivotally mounted bell crank 258 by means of' pin 260. The bell crank 258 is pivotally mounted on the frame by a pin 262. The other arm of the bell crank 258 is pivotally connected to a pair of pushrods 264 and 266 by means of pin 270 and 272. When the bell crank 258 is pivoted about pin 262 rod 264 and rod 266 are pushed or pulled depending on the direction of movement of the bell crank. This up or down movement is transmitted to the guidewheels 35, 39 by suitable linkage. Thus the are 45 of lower guidewheel 39 is reciprocally mounted in bearing 242 and a pin 247 is used to connect rod 266 with the end of the axle 45. Wheel 39 is'moved between the positions indicated in FIG. 2 by the movement of the above described linkage when the master cylinder is activated.

The upper guidewheel 35 is extended or retracted in complimentary relationship to the lower guidewheel by extending or retracting a suitable axle 241. The axle is reciprocally mounted similarly to axle 41 in a bearing 275 and is connected to pushrod 264 which is curved at its top end to provide a pin 278 connecting into the eye 279 at the lower end of axle 241.

FIG. 3 also illustrates a further aspect of the present invention in that the embodiments described herein may also be provided with an extendable and retractable support wheel for cooperation with a ramped guidebeam switch section as described and claimed in our copending application Ser. No. 861 ,843. Thus support wheel 40 may be moved to the positions indicated in phantom as 40' and 40". When both the movable support wheels and the movable guidewheels are used cooperatively in accordance with the invention a large number of rapid switch possibilities are obtained.

In an alternative embodiment of the invention the guidewheels of a rack are moved normal or transverse to the direction of travel of the rack by elevating or lowering the entire frame of the rack by changing the position of the support wheel with respect to the frame. This is done by self-contained means carried on the frame. This embodiment is illustrated in FIGS. 5, 6, 7 and 8. FIG. is an elevation view of this alternative embodiment of apparatus assembled in accordance with the present invention. FIG. 6 is a side view of the apparatus of the invention in the down position while FIG. 7 is a side elevation view of the apparatus of the invention with the guidewhwels in the up position. FIG. 8 is a bottom view of the alternative apparatus shown in FIG. 5.

A rack, generally indicated by the number 120, is formed by means of various components attached to a frame 122. The frame has a series of spaced apart wheels rotatably attached thereto. The wheels include upper guidewheels 133 and 135 and lower dual spaced apart guidewheels 137, 139, 141 and 143. The support wheels which are also rotatably mounted on the frame are indicated as 145 and 147. In accordance with the invention the guidewheels 133, 135, 137, 139, 141, 143 are caused to move in a direction normal or transverse to the direction of travel of the rack by self-contained means carried on the rack. In the alternative embodiment of the invention such movement is accomplished by raising or lowering the entire rack by changing the position of the support wheels 145, 147 to two or more different elevations as indicated in phantom in FIG. 5. Thus in this embodiment of the invention the support wheels are mounted in housings 151 and 153. The wheels 147 and 145 are driven by motors 130 and 131. The housings 151 and 153 are pivotally mounted on frame 122 by pins 155 and 157. By applying force to the housings they may be pivoted between the two positions indicated. A trunion mounted hydraulic cylinder 123 is used to activate a mechanical linkage to move the housings of the support wheels 145, 147 to at least these two different positions. As indicated in FIGS. 6 and 7 the frame, including the guidewheels, can be transversely moved up or down on the guidebeam by lifting or lowering the frame 122 with respect to the support wheels 145, 147.

The hydraulic cylinder 123 has a least two positions. The rod extension 124 of the hyraulic cylinder is connected to a pivotally mounted crank 125 by a pin 126. The crank 125 pivots about a pin 127 which is connected to the frame 122. An elongated arm 129 is pivotally connected to the lower end of the crank 125 by pin 128 and extends to a pair of pin anchored rods 101 and is connected thereto by pin 103. The pair of pin anchored rods 101 is connected to the frame 122 by pin 102 and to the support wheel housing 151 by pin 105. Thus as arm 129 is pushed or pulled the housing 151 is moved as indicated in phantom. The other housing 153 is moved in concert with housing 151 by an elongated arm 130 which is connected to a pair of pin anchored rods 106 by pin 107. This lever 106 is connected to the frame 122 by pin 108 and to the housing 153 by pin 109. When the frame is moved up or down by the action of the support wheels the guidewheels are also moved in a direction normal or transverse to the direction of movement of the rack on the guidebeam. This transverse movement of the guidewheels is useful in switching as described below.

FIGS. 9 through 14 illustrate connecting guidebeam switching sections assembled in accordance with the preferred embodiment of the present invention for cooperation with the above described racks to permit switching of the racks of the present invention. The connecting switch sections afford switching in a horizontal manner. Vertical switching may also be done as described in our co-pending US. application Ser. No. 861,843. The racks of the present invention are cantilevered on a guidebeam by means of guidewheels and support wheels. Switching is accomplished in a guidebeam switch section by programming the guidewheels by moving them traverse to the longitudinal center line of the guidebeam so that the rack will travel a predetermined path through the switch section.

The racks as discussed above are the type having a support wheel disposed well below the center of gravity of the rack. The horizontal mode of switching refers to the overall disposition of the rack through the connecting switch section. Thus when referring to a horizontal switch section it is understood that there may be if desired vertical displacement of the rack immediately downline of the horizontal switch to provide for a vertical movement to a downline guidebeam. It is evident that while the switch sections are described as proceeding from an upline guidebeam to one of two more downline guidebeams, the opposite also can be true. That is, by reversing the direction of travel and the sequencing of displacing the guidehwheels or support wheels and by reversing the elements of the connecting switch section the rack may come from one of two spaced apart upline guidebeams through a connecting switch section to merge into a single downline guidebeam.

A horizontal switch for switching the racks of the present invention is illustrated in FIG. 9, FIGS. 9A to 9E, FIG. 10 and FIGS. 10A and 103. A mainline guidebeam is generally indicated by the number 160. Two substantially horizontally spaced apart guidebeams, 161 and 162, are shown downline from the upline guidebeam 160. A connecting switch section which provides for selectively directing a rack from upline guidebeam to either of the two downline guidebeams, 161 or 162, is located between the upline guidebeam and the downline guidebeams. The switch portions are illustrated in section in FIGS. 9A-9E and FIG. 10A. The wheels of the rack, as they move into the connecting switch section, select the path through which they will proceed. There are no moving parts in the guidebeam switch section itself. Thus the guidewheels of the rack by their position on the guide running surface of the guidebeam switch section select the path on which the rack will travel through the connecting switch section. By virtue of making such a selection, the rack is directed to either of the desired downline guidebeams. As described above the self-contained means of the rack move both the upper and lower guide wheels in complementary fashion in a vertical manner to select the desired guide wheels running surface. This vertical movement is at a right-angle or normal to the direction of travel of the rack and moved the guide wheels transversely on the guidebeam with respect to the longitudinal centerline of the guidebeam.

The movement of the rack through the horizontal switch section, illustrated in FIGS. 9, 9A to 9E and FIGS. 10, A and 108, will now be described in detail. The path of the rack through the switch section will be described in moving the rack from upline guidebeam 160 to downline guidebeam 162. Assume first that it is desired to move the rack from upline guidebeam 160 to downline guidebeam 161. The guidewheels of the rack are programmed as herein before described to follow the appropriate guidewheel running surfaces. Thus referring to FIG. 9 it is seen that the guidewheels of the rack in normal running position will be moving over upper guide running surface 169 and lower guide running surface 167. The support wheel travels on support wheel running surface 165. Since it is desired to move the rack from upline guidebeam 160 through the connecting switch section to downline guidebeam 161 in substantially a horizontal mode, the guidewheels of the rack are maintained in position to follow the lower portion 170 of upper guide running surface 169 which develops between sections 9C and 9D. In this regard upper guide running surface may be wide enough so that two surfaces 170 and 173 may develop. The lower guidewheels follow the lower portion of surface 167 through the connecting switch section. In this manner the rack is transferred to the guidebeam 161 as illustrated in FIG. 9E and FIGS. 10A and 108. Thus by simply maintaining the guidewheels of the rack in the down or lower position the rack is directed to the selected downline guidebeam 161. If the guide wheels were in the up position as the rack approached the switch and it was desired to switch to guidebeam 161, the self-contained means would be activated to move the guidewheels vertically down the guidewheel running surfaces prior to reaching the switch section.

If it is desired to direct the rack from upline guidebeam 161 to downline guidebeam 162, both the upper and lower guidewheels are elevated on their respective running surfaces of the guidebeam so that the upper guide wheels will contact upper portion 173 of the guide running surface which develops from guide running surface 169 between FIGS. 9C and 9D. The lower guide wheels will then clear surface 167. A second lower guide running surface 168 is developed between FIGS. 9A and 9B and this surface is used by the upper of the lower dual guide wheels. This upper wheel of the dual lower guide wheels is the idler wheel 80, 82 of FIG. 3 and 141, 143 of FIG. 5. A standard running surface as shown in FIG. 9A and FIG. 10B is developed downline of the section shown in FIG. 9E and the rack is returned to the normal running position on the guidebeam with the guidewheels left in position or changed as desired.

A combined switch for switching the rackS of the present invention is illustrated in FIG. 11, FIGS. llA-llE, FIG. 12, FIG. 12A, FIG. 13, FIGS. l3A-13E, FIG. 14 and FIGS. 14A and 14B. The combined switch utilizes both extendable and retractable support wheels and vertically movable guidewheels to provide for passing the rack through numerous closely spaced switches without having to rapidly reset either the support wheels or the guidewheels. Thus the switch section illustrated in FIGS. 11 and 12 utilizes a ramped support wheel running surface to switch or pass through a gap. Downline of this switch section as illustrated in FIGS. 13 and 14 a guidewheel switch section is connected and utilizes vertically movable guidewheels to switch the rack. In this manner a rack which passes straight through the switch section of FIGS. 11 and 12 can be further switched in the FIG. 13 and 14 switch by a predetermined setting of the guidewheels prior to entering the support wheel switch section without moving the support wheels after entering the support wheel section.

The switch section Of FIGS. 11 and 12 will be first described in detail. A mainline guidebeam is generally indicated by the number 180. Two substantially horizontally the upline guidebeam 10. A connecting switch guidebeam section which provides for selectively directing a rack from upline guidebeam to either one of the two downline guidebeams, 181 or 182, is located between the upline and downline guidebeams. The switch portion is illustrated in FIGS. 1 lA-l 1E. The predetermined wheels of the rack, as they move into the connecting switch section, select the path through which the rack will proceed. Thus the extendable and retractable'support wheels of the rack select the path on which it will run through the first portion of the combined connecting switch section. By virtue of making such a selection, the rack is directed to either of the desired downline guidebeams.

The operation of the rack through the horizontal switch section illustrated in FIGS. 11 and 12 will now be described in detail. The path of the rack through the switch section will be described in moving the rack from upline guidebeam 180 to both downline guidebeams 181 and 182.

Assume for the purposes of description that it is desired to direct a rack from upline guidebeam 180 to downline guidebeam 181. The support wheels of the rack are programmed to follow the appropriate support wheel running surface. Thus referring to FIG. 11A it is seen that a support wheel of the rack in normal running position is moving over support wheel running surface 185. The support wheel is in retracted position with respect to the rack. An upper guide running surface 189 is provided for the upper guide wheels. A lower guide running surface 187 is provided for the lower guide wheels and a support running surface 185 is provided for the support wheels. Since it is desired to move the rack from upline guidebeam 180 through the connecting switch section to downline guidebeam 181 in substantially a horizontal mode the support wheel of the rack is maintained in a normal retracted position so as to ride on the normal portion of the horizontal support running surface 185.

As the rack proceeds downline through the connecting section to a position illustrated in FIG. 11 B the support wheel running surface 185 ramps down. The lower guidewheels continue to run on surface 187 while the upper guidewheels continue to run on surface 189 to hold the rack in cantilevered the guidebeam. The support wheel running surface 185 has lowered to the required extent as illustrated in FIG. 11C. Again the rack continues to move in cantilevered fashion using running surfaces 187 and 189 for the lower and upper guidewheels respectively. In FIG. 11 D and FIG. 11E the connecting switch section begins to provide a horizontally diverging path for the rack to follow downline guidebeam section 181. Thus the running surfaces 189, 185 and 187 begin to move out and away from the other downline guidebeam 182. Therefore a rack carried by the appropriate wheels on such surfaces also moves away from the other downline guidebeam 182.

In FIG. 11E the rack has moved substantially away from the guidebeam 182 and is cantilevered on surfaces 189, 185 and 187. The sectional view FIG. 12A illustrates the running surfaces of the downline guidebeam 181 as the guidebeam returns to its normal form.

When it is desired to move a rack from upline guidebeam 180 to the other downline guidebeam 182 the support wheel of the rack is extended as the rack moves into the portion of the connecting switch section illustrated in FIG. 1 1A. The support wheel is moved so that it can run on running surface 190 as shown in .FIG. 11B while the upper guide wheels move on surface 189. It is of course within the scope of the invention to have a running surface 190 be two running surfaces thus allowing 3 directional switching without altering the support wheels in the switch section. A new surface 188 is developed for the so-called idler wheel which is the upper of the lower dual guidewheels. In FIG. 11C the lower guide running surface 187 ramps down and the lower of the dual lower guide wheels begins to come off of surface 187 since the support wheel is now running on the support running surface 190. Running surface 188 is available for the idler wheel of the lower guide wheels through all portions of the switch from before FIG. 118 to after FIG. 11E. The lower guide running surface 187 has dropped down far enough to free the lower guide wheels by FIG. 11C when the support wheel is on surface 190. Between FIG. 11C and FIG. 11E the running surfaces leading to downline guidebeams 181 and 182 diverge. In FIG. 11E the upper guide wheels are located on surface 193 which has smoothly developed and diverged from surface 189. The lower of the dual lower guide wheels are above surface 187 and therefor free to move in over surfaces 187 and 185 without touching them. Thus a window or gap for passing the rack through guidebeam 181 onto guidebeam 182 matures between FIG. 11C and FIG. 1 IF. A rack located at FIG. 1 1E and having its support wheel on surface 190 would have the upper guide wheels on surface 193 and its lower idler wheel on surface 188. The body portion of the rack clears both the upper and lower portions of guidebeam 181 and the rack may now pass along the guidebeam 182 which returns to standard mainline configuration.

After passing on to a downline guidebeam it may be desirable to immediately incorporate another switch section into the system. Thus the switch section illustrated in FIGS. 13 and 14 embodiment may be connected to guidebeam 182 immediately downline and switching done by vertical guidewheel setting without the need of rapidly moving the support wheel. This is the combined mode of switching in accordance with the present invention. Thus by proper guidewheel setting the rack can be switched from guidebeam 182 of FIG. 13 to downline guidebeam 361 or 362.

The mainline guidebeam is generally indicated by the number 182. Two substantially horizontally spaced apart guidebeams, 361 an 362, are shown downline from the upline guidebeam 182. A connecting switch section which provides for selectively directing a rack from upline guidebeam 182 to either of the two downline guidebeams, 361 or 362, is located between the upline guidebeam and the downline guidebeams. The switch portions are illustrated in section in FIGS. 13B 13 E and FIG. 14A. The wheels of the rack, as they move into the connecting switch section, select the path through which the rack will proceed. There are no moving parts in the guidebeam switch section itself and it is not necessary to reposition the support wheels. Thus the guidewheels of the rack by their position on the guide running surface of the guidebeam switch section select the path on which the rack will run through the connecting section. By virtue of making such a selection, the rack is directed to either of the desired downline guidebeams. As described above the selfcontained means of the rack moves both the upper guide wheel and the lower of the dual lower guide wheels in complementary fashion in a vertical manner on the guidebeam to select the desired guide wheel running surface. This vertical movement is at a right angle or normal to the direction of travel of the rack along the longitudinal centerline of the guidebeam.

The movement of the rack through the horizontal switch section, illustrated in FIG. 13, FIGS. 13A-13E, FIG. 14, and FIGS. 14A and 14B, will now be described in detail. The path of the rack through the switch section will be described in moving the rack from upline guidebeam 182 to downline guidebeam 361 and from upline guidebeam 182 to downline guidebeam 362. Assume first that it is desired to move the rack from upline guidebeam 182 to downline guidebeam 361. The guidewheels of the rack are programmed as herein before described to follow the appropriate guidewheel running surfaces. Thus referring to FIG. 13A it is seen that the guidewheels of the rack will be moving over the lower portion 369 of the upper guide running surface and lower guide running surface 367. The support wheel travels on support wheel running surface 365. Since it is desired to move the rack from upline guidebeam 182 through the connecting switch section to downline guidebeam 361 in substantially a horizontal mode, the guidewheels of the rack are maintained in position to follow the lower portion 369 of upper guide running surface which diverges between sections 13C and 13D. The lower guidewheels follow surface 367 through the connecting switch section. In this manner the rack is transferred to the guidebeam 361 as illustrated in FIG. 13E and FIGS. 14A and 14B. Thus by simply maintaining the guide wheels of the rack in the down or lower position the rack is directed to the selected downline guidebeam 361.

If it is desired to direct the rack from upline guidebeam 182 to downline guidebeam 362, both the upper guide wheels and the lower of the dual lower guidewheels are elevated on their respective running surfaces of the guidebeam so that the upper guide wheels will contact the upper portion 373 of the upper guide running surface which diverges between FIGS. 13C and 13D and, being elevated, the lower guide wheels will clear surface 367. A second lower guide or idler running surface 368 is developed between FIGS. 13A and 13B and this surface is used by the idler or upper of the lower dual guide wheels. This upper wheel of the dual lower guide wheels is the idler wheel 80, 82 of FIG. 3 and 141, 143 of FIG. 5. A standard running surface shown in FIG. 13A and FIG. 14B is developed downline of the section shown in FIG. 13E and the rack is returned to a normal running position on the guidebeam, the guidewheels and support wheel left in position or changed as desired.

An alternative embodiment of apparatus of the present invention incorporates a support wheel at the top of the rack. Vertically movable guide wheels and if desired extendable and retractable support wheels are used to switch from a mainline guidebeam section either to the left or to the right in a horizontal fashion to a diverging downline guidebeam and to switch from the mainline guidebeam section vertically either up or down to a diverging downline guidebeam. Also the opposite course may be followed by a rack through such a switch section (or obviously a mirror image switch section) constructed to provide for merging from two downline guidebeams into a main upline guidebeam. In either a merging or diverging mode switching is accomplished by the rack without the use of moving parts in the connecting guidebeam switch section. Vertically movable guide wheels on the rack and also if desirable extendable and retractable support wheels of the rack, provide for selecting one of two or more paths on a guidebeam switch section to thus determine the course that the rack will take through the connecting switch section. I

In FIG. 15 and FIG. 16 the alternative embodiment of apparatus assembled in accordance with the present invention is shown in schematic' form. FIG. 15 is a side elevation and FIG. 16 is an end elevation, partially in section, showing an alternative rack generally indicated by the number 220 attached to and in running position on an alternative elongated guidebeam which is generally indicated by the number 230. The guidebeam is formed to provide a path in the transportation system and serves to carry the running surfaces on which the rack 220 moves. The rack 220 includes a frame member 222 having a number of sets of spaced apart wheels rotatably attached thereto. The sets of wheels include the upper guide wheels 233 and 333; the lower guide wheels 239 and 339; the support wheels 238 and 338 and the auxiliary support wheels 240 and 340. The support wheels 238 and 338 as will hereinafter be discussed in detail are usually driven by a power source and therefore also function as drive wheels to move the rack along the guidebeam. The alternative embodiment rack has spaced apart upper guide wheels 233 and 333 and lower guidewheels 239 and 339. The guide wheels .are positioned on the frame at suitable intervals depending on the load and the length of the rack. It is usually desirable to have at least two upper guide wheels and two' lower guide wheels and two support wheels for each rack. Dual upper auxiliary support wheels 240 and 340 are also provided for each support wheel in order that certain switching operations may be accomplished by this alternative rack.

As in the preferred embodiment of apparatus, the alternative guidebeam 230 is held in desired position by suitable support means such as for example by a series of columns such as column 244, spaced apart along the right of way. The guidebeam 230 may be composed, for example, of prestressed concrete sections resting end to end on a series of supports such as column 244. Suitable overall dimensions for such prestressed sections as a guide to understanding the present invention have been found to be about 8 high by 6' wide and 100 long.

The guidebeam 230 provides at least three spaced apart running surfaces for the rack. Thus on each mainline right of way portion of the alternative guidebeam there is provided an upper guide running surface 234, a lower guide running surface 231 and a support wheel running surface 242. The upper guide running surface 234 and the lower guide running surface 231 have sub stantially vertically disposed running surfaces to accomodate the upper and lower guide wheels respectively. The support wheel running surface 242 is in a substantially horizontal plane to accommodate the support wheels. As illustrated in FIG. 15 and FIG. 16, the self-powered rack 220 is adapted to be held and to be moved on the three running surfaces of the guidebeam 230 is cantilever fashion. Thus the upper guide surface 234 is formed on a vertical inward facing wall of the guidebeam 230 while the lower guide running surface 231 is formed on a vertical outward facing wall of the guidebeam 230. The upper guide wheels 233, 333 and the lower guide wheels 239, 339 cooperate with the support wheels 238, 338 to position the rack in cantilever fashion on the guidebeam 230.

The rack 220 is driven along the guidebeam 230 by means of a suitable power source supplying power to the support wheels. As noted, it is preferred in the alternative embodiment of apparatus to use a wheel which rotates on a horizontal axis as a drive wheel. It is of course possible to provide either or both the upper and lower guide wheels with power. Motive power is supplied to the support wheel 238 by a suitable power source. Such a power source may for example be an electric motor or an internal combustion engine. Such a suitable power source is schematically illustrated in FIG. 15 by the box indicated by the number 248. If it is desired to drive more than one support wheel, then a second power source 246 may be utilized to drive wheel 338. Suitable drive train means are provided to connect power source 246, 248 to the support wheels 238, 338. Control means 250 are preferably carried on the rack 220 to control the power sources 246 and 248 and the movement of the wheels and thus the rack 220 along the guidebeam 230. Control means 250 is preferably electrically activated and in many instances will be tied into a computer network so that a number of racks may be moved at closely spaced intervals along the guidebeam system.

This alternative form of the present invention provides for switching a rack 220 having a top support wheel from a mainline upline guidebeam to one of two or more diverging downline guidebeams in a horizontal mode and also to be merged from two upline guidebeams to a single downline guidebeam in a horizontal mode. The vertically movable wheel configuration of the upper and lower guide wheels permit continuous contact of the respective upper and lower guide wheels to selected surfaces during the entire switching operation as the rack is switching from one guidebeam to another through the switch section. In accordance with the present invention self-contained means carried on the rack are utilized to raise or lower the guide wheels. The rack may be switched horizontally from a main guidebeam to the left or to the right to diverting downline guidebeams, or may be continued through such connecting switch section on the mainline guidebeam. The switch section can be modified so that such horizontal switching may be accomplished into a through mainline guidebeam from guidebeams merging from the left or the right. When utilizing a rack having both self-contained means for vertically moving the guide wheels as disclosed above in detail in the description of the preferred embodiment of the present invention and having extendable and retractable support wheels, and dual vertically spaced apart upper and lower guidewheels, such as taught in our application Ser. No. 861,843 and adaptable for use with the present invention, the alternative upper support wheel rack may be moved rapidly through a very complex interchange or a series of closely spaced-apart switch sections and switched vertically or horizontally or both in sequence without the need to reset the wheels after each portion of the switch section is passed. For example the guide wheels on a rack can be programmed to make the first possible right hand horizontal turn of FIG. 1. Then without resetting the guide wheels or support wheels the rack can be quickly switched through up to five or more of the next diverging horizontal guidebeams by proper prior programming or setting of the guide wheels and support wheels. In a similar manner vertical switching can proceed or follow horizontal switching by proper prior programming or setting of the support wheels and guide wheels as illustrated downline in FIG. 1. Utilizing both moving guidewheels and moving support wheels many combinations of switching are provided in accordance with the present invention. FIG. 1 is used to illustrate some of the modes of switching possible in accordance with the invention.

The guidewheels and the support wheels of this alternative embodiment of apparatus are moved in their respective modes as fully discussed and illustrated in the detailed description of the present invention. Therefore a repeated detailed description of such structure will not be necessary. Thus self-contained means are provided on the rack for displacing the guidewheels in a direction normal to the direction of travel of the rack over a guidebeam. The movement is generally in a vertical direction with respect to the longitudinal centerline of the guidebeam. This transverse or vertical movement is done when it is desired to switch a rack from one guidebeam to another and realignment of the guidewheels is necessary to select the proper path through the switch section. In one aspect of the present invention the upper and lower guidewheels are moved up or down with respect to the rack. Appropriate linkage is used to extend or retract the axles of the guidewheels to thus move the guidewheels normal to the direction of movement of the rack and raise or lower'the guidewheels with respect to the running surface of the guidebeam. In another aspect of the invention the guidewheels of a rack are moved normal or transverse to the direction of travel of the rack by elevating or lowering the entire frame of the rack by changing the position of the support wheel with respect to the frame.

A horizontal switch for this alternative embodiment of apparatus is illustrated in FIG. 17, FIGS. 17A-l7F,

FIG. 18 and FIGS. 18A and 188. In this switch a rack may be directed from upline guidebeam 410 to either of a pair of diverging downline guidebeams 412 and 414. If it is desired for example to direct a rack from guidebeam 410 to guidebeam 414 the following running surfaces would be utilized. A support running surface 420 is used as the mainline support running surface. Guidewheel running surfaces 430 and 431 are provided for the upper guidewheels and a guidewheel running surface 424 is provided for the lower guidewheels. When it is desired to go to guidebeam 414 the guidewheels are moved up if they are not already in such position. An upper guide running surface 431 begins to diverge between FIGS. 17D and 17E. This serves to carry the upper guidewheels on running surface 431 through the switch section to guidebeam 414. The lower guidewheels run on surface 424 through the entire connecting switch section above surface 436 to 116 guidebeam 414. The support wheel follows surface 420.

When it is desired to switch the rack from guidebeam 410 to guidebeam 412 the guidewheels are moved vertically down or maintained in such position if already there. The upper guidewheels follow surface 430 and the lower guidewheels follow surface 436. A new auxiliary horizontal running surface 432 develops betwen FIGS. 17A and 17B and the dual upper auxiliary support wheels 240 and 340 of FIGS. 15 and 16 run on this surface through the portion of the window section of the switch when the main support wheels come off surface 420. The auxiliary support wheels, of course, may be powered or momentum may be used to carry the rack through this portion of the switch. The upper guidewheels operate on surface 430 through the connecting switch section while the lower guidewheels pick up surface 436 in FIG. 17D and utilize this surface through the window section of the switch. The rack is thus switched to guidebeam 412.

Although specific embodiments of the present invention have been described in detail the invention is not to be limited to any such specific embodiments but is meant to include all embodiments coming within the scope of the appealed claim.

We claim:

1. A cantilevered transportation system having nonmoving connecting switch sections comprising a main guidebeam, a first spaced apart guidebeam, a second spaced apart guidebeam, all of said guidebeams having an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface formed thereon, a connecting guidebeam switch section extending between said main guidebeam and each of said spaced apart guidebeams, first nonmoving connection running surfaces on said guidebeam switch section between said main guidebeam and said first spaced apart guidebeam, said first running surfaces comprising an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface, each of said first running surfaces being connected between the counterpart running surfaces of said main guidebeam and said first spaced apart guidebeam, second nonmoving connecting running surfaces on said connecting guidebeam switch section between said main guidebeam and said second spaced apart guidebeam, said second running surfaces comprising an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface, each of said second running surfaces being connected between the counterpart running surface of said main guidebeam and said second spaced apart guidebeam, a rack having upper and lower guidewheels and support wheels for use in moving on the running surfaces of said guidebeams and self-contained means carried on said rack for raising or lowering the guidewheels of said rack with respect to a guidebeam to move the rack through said guidebeam switch section between said main guidebeam and one of said spaced apart guidebeams.

2. The system of claim 1 further characterized in that the rack has sets of dual vertically spaced apart lower guidewheels.

3. The system of claim 1 further characterized in that the main guidebeam is an upline guidebeam and the spaced apart guidebeams are diverging downline guidebeams.

4. The system of claim ll further characterized in that the main guidebeam is a downline guidebeam and the spaced guidebeams are merging upline guidebeams.

5. The system of claim 3 further characterized in that the downline guidebeams are horizontally spaced apart.

6. The system of claim 4 further characterized in that the upline guidebeams are horizontally spaced apart.

7. The system of claim 1 further characterized in that the self-contained means carried on said rack are extendable and retractable guidewheels movable in tandem between at least two positions.

8. The system of claim 1 further characterized in that the support wheels are located near the lower part of said rack.

9. The system of claim 2 further characterized in that axles of each of the support wheels are located between the set of dual lower guide wheels.

10. The system of claim 1 further characterized in that the support wheels are located near the upper part of said rack.

11. The system of claim 1 further characterized in that the self-contained means carried on said rack to raise or lower the guidewheels with respect to a guidebeam re vertically movable support wheels relative to the guide wheels of said rack.

12. The system of claim lll further characterized in that the support wheels are mounted in a housing which is pivoted between at least two positions relative to the guide wheels of said rack to raise or lower said guidewheels.

13. The system of claim 1 further characterized in that the support wheels of said rack are extendable and retractable normal to the direction of travel of said rack between at least two positions.

14. The system of claim ll further characterized in that the running surface of the connecting guidebeam switch section contain at least one gap to pass portions of a rack and that dual spaced apart wheels cooperate to bridge such gap as the rack is moved through the connecting switch section.

15. The system of claim 2 further characterized in that the support wheels are extendable and retractable between at least two positions.

16. The system of claim 2 further characterized in that the running surfaces of the connecting guidebeam switch section contain at least one gap to pass portions of a rack and the dual spaced apart lower guide wheels cooperate to bridge such gap as the rack is moved through the connecting switch section.

17. The apparatus of claim 16 further characterized in that the support wheels are extendable and retractable between at least two positions. 

1. A cantilevered transportation system having nonmoving connecting switch sections comprising a main guidebeam, a first spaced apart guidebeam, a second spaced apart guidebeam, all of said guidebeams having an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface formed thereon, a connecting guidebeam switch section extending between said main guidebeam and each of said spaced apart guidebeams, first non-moving connection running surfaces on said guidebeam switch section between said main guidebeam and said first spaced apart guidebeam, said first running surfaces comprising an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface, each of said first running surfaces being connected between the counterpart running surfaces of said main guidebeam and said first spaced apart guidebeam, second nonmoving connecting running surfaces on said connecting guidebeam switch section between said main guidebeam and said second spaced apart guidebeam, said second running surfaces comprising an inwardly facing vertical upper guide running surface, an outwardly facing vertical lower guide running surface and a substantially horizontal support running surface, each of said second running surfaces being connected between the counterpart running surface Of said main guidebeam and said second spaced apart guidebeam, a rack having upper and lower guidewheels and support wheels for use in moving on the running surfaces of said guidebeams and self-contained means carried on said rack for raising or lowering the guidewheels of said rack with respect to a guidebeam to move the rack through said guidebeam switch section between said main guidebeam and one of said spaced apart guidebeams.
 2. The system of claim 1 further characterized in that the rack has sets of dual vertically spaced apart lower guidewheels.
 3. The system of claim 1 further characterized in that the main guidebeam is an upline guidebeam and the spaced apart guidebeams are diverging downline guidebeams.
 4. The system of claim 1 further characterized in that the main guidebeam is a downline guidebeam and the spaced guidebeams are merging upline guidebeams.
 5. The system of claim 3 further characterized in that the downline guidebeams are horizontally spaced apart.
 6. The system of claim 4 further characterized in that the upline guidebeams are horizontally spaced apart.
 7. The system of claim 1 further characterized in that the self-contained means carried on said rack are extendable and retractable guidewheels movable in tandem between at least two positions.
 8. The system of claim 1 further characterized in that the support wheels are located near the lower part of said rack.
 9. The system of claim 2 further characterized in that axles of each of the support wheels are located between the set of dual lower guide wheels.
 10. The system of claim 1 further characterized in that the support wheels are located near the upper part of said rack.
 11. The system of claim 1 further characterized in that the self-contained means carried on said rack to raise or lower the guidewheels with respect to a guidebeam re vertically movable support wheels relative to the guide wheels of said rack.
 12. The system of claim 11 further characterized in that the support wheels are mounted in a housing which is pivoted between at least two positions relative to the guide wheels of said rack to raise or lower said guidewheels.
 13. The system of claim 1 further characterized in that the support wheels of said rack are extendable and retractable normal to the direction of travel of said rack between at least two positions.
 14. The system of claim 1 further characterized in that the running surface of the connecting guidebeam switch section contain at least one gap to pass portions of a rack and that dual spaced apart wheels cooperate to bridge such gap as the rack is moved through the connecting switch section.
 15. The system of claim 2 further characterized in that the support wheels are extendable and retractable between at least two positions.
 16. The system of claim 2 further characterized in that the running surfaces of the connecting guidebeam switch section contain at least one gap to pass portions of a rack and the dual spaced apart lower guide wheels cooperate to bridge such gap as the rack is moved through the connecting switch section.
 17. The apparatus of claim 16 further characterized in that the support wheels are extendable and retractable between at least two positions. 